Bobbi Broker Company charges a fee for bringing together Ace Construction Company and First Bank. The parties agree that Bobbi earns her fee when Ace and First "agree" to the terms of the construction mortgage. However, Bobbi can receive different types of documents to "settle" this matter: (a) a non-interest bearing, unsecured "negotiable" note in payment of the fees earned, which is payable over the time period of the related construction mortgage; (b) a non-negotiable note payable over the same time period as in case (a); or (c) a commitment letter, not contingent upon the "future event" of the borrower receiving certain construction draws. A commitment letter informs the borrower that the loan has been approved, as long as certain conditions are met. It is similar to a cover letter to the actual contract to be signed by both the lender and the borrower. Bobbi asks the accountant when to recognize revenues under each of these scenarios